This invention relates to a cable clamp and more particularly, to a cable clamp for use with mobile telephone masts.
Cable clamps commonly are provided as single piece devices, or two piece devices, which fit around a cable and then the whole arrangement comprising the clamp and the cable, is fitted by a separate device to a support structure, such as a cable mast for mobile phones. Such devices have the disadvantage that cable needs to be threaded through the clamp, which can make installing cables both difficult and time consuming. Also, in the case of two piece clamp connectors, it is necessary to separate the two pieces of the connector while the cable is being positioned in the connector. This can have the problem that when the two pieces are to be connected together again, once the cable is positioned, it is necessary to position the two parts of the connector so that the connecting parts on the two pieces are brought into a position where they will join. This can involve a degree of trial and error in locating the connecting parts and it may even be the case that a person installing the cable connector may not actually connect the two parts at all.
Cable clamps are known, such as those discussed in GB 2296393, which comprise a cable clamp having two hinged parts, which are fastened around a cable that is inserted in the clamp. However, this arrangement includes a pair of clamp elements, which have to be screw-driven down to hold the cable within the clamp. The use of a separate screw-mechanism increases the difficulties of installing such clamps, as it may not be easy to access the screw-mechanism, which could result in poor fixing of the two clamp halves together. Also it is necessary to ensure that the screw and receiving mechanism are in alignment so that the two parts will be held together properly. Should poor fixing occur the cable could eventually work loose from the clamp, with the consequence that repairs would have to be carried out to ensure that the cable is properly secured to a cable mast.
In accordance with the present invention, there is provided a cable clamp comprising first and second body elements, each defining a cable recess so that when the elements are brought together with the recesses aligned, they substantially encircle a cable location, with at least one of the elements having a projection and the other a co-operating opening whereby in the aligned position of the elements, the projection is received in said opening, but in a rotated position of the elements, the projection seats on the other of the elements to hold the elements apart to allow access to the cable location.
Preferably, the projection and opening are interference fittable when brought into a mating arrangement. In addition, the cable recesses extend around opposing portions of the outer surface of the cable.
Preferably, first and second elements each have respective projections in the form of male members comprising split pins extending from a first surface of each respective element, said first surface defining the opening for a male member on the opposed element which is adjacent the male member.
It is particularly preferred that the first and second elements have at least one pair of male and female members with the male members diagonally opposed to one another on the first surface whereby when in mating relationship the male and female members align along their length to form a pin member extending between the first and second elements.
For example, the male members may be inter-engaging surfaces so that as one engages its opposed pair, it is located above the associated opening. Thus, if the male members are semi-circular in section, their flat surfaces engage.
The male and female members may be integrally molded on the elements making up the cable clamp connector. In a second aspect, the invention consists in cable clamp comprising at least two elements connectable together to form said cable clamp, with at least one of said elements having a ratchet mechanism on an outer surface of said element.
The ratchet mechanism on a surface of the cable clamp can be positioned to abut against a face of a second cable clamp connector which is positioned against the first cable clamp. The ratchet mechanism allows the first and second cable clamps to be rotatably positioned relative to one another in a controlled manner.
From a third aspect, the invention consist in a cable clamp comprising first and second elements, each defining a cable recess so that when the elements are brought together with the recesses aligned, they substantially encircle a cable location, at least one of the elements having a projection and a cooperating opening to secure the elements together when the first and second elements are brought into a mating arrangement, wherein one or more of the elements also has a ratchet mechanism on an outer surface which when said outer surface is positioned against a correponding outer surface of a further element, enables both elements to move relative to one another.
The present invention and embodiments thereof, provide a cable clamp, which can be locked into position by a single action. The use of a single action securing mechanism avoids the need for separate securing means for screwing clamping members together, which is a major disadvantage of the prior art. In addition the present invention provides a twist and hold mechanism whereby the positioning of at least one of the projections on the first or second element, or indeed on both elements, allows the two recessed members to be held apart while the cable is inserted in the recess. This feature has a major advantage in that the need to position connecting members so that they engage is negated, which means that the clamp is easier, quicker and safer to install, especially is situations where access is not readily available.
Further, the ratchet mechanism that may be provided on the cable clamp of the present invention, means that stacked clamps may be positioned relative to one another by a simple twisting operation. The use of such a ratchet mechanism again has the advantage of providing a cable clamp connector, which is easy to install, as access for fitting the clamp is not crucial for installation. Also as the cable clamp of the present invention avoids the need for many fixing parts, the clamp can be easily installed, thereby reducing the need for specially trained installation engineers. This feature has major advantages in less developed countries where there may be a shortage of skilled workers.